Smoking - what were the rules?

[brakedwell]

I forgot to mention there was a hell of a clang when the OXO tin hit a propellor.

Found this slide taken over Turkey at 10000' with Mount Ararat in the distance.

[HarryMann]

The exception might be the low level bomber runs like 617's Dambuster sorties or the USAF Ploesti raids but these would NOT be the norm.

I've heard Liberators were known to just pour fuel all over the place - so I doubt much smoking went on during the Ploesti raids...